Oxidation of Guaiacol by Heterogeneous Photo-Fenton Process

The effect of the heterogeneous UV/Fenton system on degradation of model compound of lignin guaiacol was investigated using Fe-exchanged γ-Al2O3 as catalyst which was prepared by impregnation method,and compared with the effect of heterogeneous Fenton system. It is found that heterogeneous photo-Fenton process was effective for the degradation of guaiacol with stable structure. At the ambient temperature,the initial pH=6.3,two times of stoichiometric quantities of H2O2,1 g/L catalyst (the Fe3+ and H2O2 molar ratio was 1:31.6),50 mg/L guaiacol solution,the removal of guaiacol reached as high as 100% in 60 min. TOC removal by using heterogeneous UV/Fenton and heterogeneous Fenton process achieved 94.3% and 17.2% in 90 min respectively,because UV-light and Fenton's reagent had synergetic effect enhancing the oxidative ability of the process. The TOC removal rate was slower than the guaiacol removal rate in the same time. This indicated that guaiacol was not immediately mineralized to CO2 and H2O,but to smaller molecular intermediates and finally could be completely mineralized.